Rca Ctc-15

[Charlie]

I called the guy that has the old tv shop in town and gave him some numbers. He cross-ref them and found he still had some NOS focus rectifiers from way back. He pulled them off the shelf and tried checking them the same way I did, but got the same results I did... nothing.

Is there a reason for not being able to check these on a meter?

He is going to save what he has for me incase I need spares since he no longer uses them.

[andy]

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[tubesrule]

Hi Charlie,
Older high voltage diodes are usually made up of a string of lower voltage diodes in series to get the desired breakdown voltage. A meter usually uses about 2 volts to measure a diode which is sufficient for any type of single diode. When they're in a chain like this you need to provide enough voltage for the sum of the diodes. Using 0.7 volts each, and guessing at 5 diodes, you would need more than 3.5 volts to forward bias the focus rectifier. You can try using a 9 volt battery and a resistor sufficient to keep the current to a milliamp or so, and set the meter to DC current to check the diode.

Darryl

[tubesrule]

Looks like Andy beat me to it

[Charlie]

Thanks guys... I am going to continue with the assumption that it's good.

During all of this, I did discover a 100k resistor connected to the focus coil that was way off... it was reading 16k. Hmmm... maybe this was the reason the old flyback kept getting so hot after running it for a while.

[Charlie]

I got the new flyback installed today, and so far, all is looking good. No bad surprises when I fired it up, and it has been running a little more than an hour with hardly any heat at all. There is a slight warmth, but feels like it should be normal. Nothing compared to the heat the old flyback was putting out! Currents at the HO tube and HV regulator are all within spec and steady. Focus voltage is good, too.

Can't say much for the picture right now. The crt this thing is currently connected to is very weak and has severe cataracts. The raster fills the screen and the color is working, so that's all I can say for the picture.

As of now, this chassis still has all of the original lytics in it. I have been debating whether or not to install the new ones. I probably will.

The cabinet is ready for stain, so, i'll start on that tomorrow.

At least my flyback troubles are solved!

[polaraman]

Charlie,

I still need the convergence magnets. Plus the ring with the slides that goes behind that. My set would be complete then. Have just replaced the vertical output transformer in mine. I just got outbid for a CTC 15 in maryland.

What year Duster is that? My folks had a 72 lemon yellow twister with a 318 and 3 speed combination. It had the houndstooth interior. I want to get one and recreate my parents car.

polaraman

[Charlie]

Originally Posted by polaraman

Charlie,

I still need the convergence magnets. Plus the ring with the slides that goes behind that. My set would be complete then. Have just replaced the vertical output transformer in mine. I just got outbid for a CTC 15 in maryland.

What year Duster is that? My folks had a 72 lemon yellow twister with a 318 and 3 speed combination. It had the houndstooth interior. I want to get one and recreate my parents car.

polaraman

I'll be able to fix you up with those items.

The Duster is 72. Houndstooth with a yellow exterior? Man I bet yall had to wear shades whether you were in or out of the car!